Fraction of slow rotators as a function of the dimensionless time t. The green points are the binned-collected observational data in this work. Black triangles are simulation data from the Zhou et al. (2025) model, where the YORP timescale is manually increased by ten times compared to the normal YORP timescale. The red line is the fit function in Eq. (5). The shaded area is the 95% confidence interval of the fit. We do not show individual families because data are not sufficient for a statistical analysis.